Bok Choy Calories & Nutrition Calculator

Raw bok choy contains 13 kcal per 100g — even lower than lettuce (14 kcal for iceberg, 17 kcal for romaine), cucumber (15 kcal), and celery (16 kcal). It is 96% water by weight, making it one of the most hydrating vegetables available ^[1].

Cooked bok choy drops to 12 kcal per 100g — the boiling process slightly dilutes the already-minimal calorie content. One cup of cooked bok choy (170g) contains only 20 kcal, making it essentially calorie-free for tracking purposes unless you're consuming very large quantities.

For food journaling, bok choy's calorie contribution is typically negligible compared to the cooking oil, sauces, or broth it's prepared with. A tablespoon of sesame oil (120 kcal) added to a stir-fry exceeds the calories of 1 kilogram of raw bok choy.

Raw bok choy contains 105mg calcium per 100g — and unlike spinach (99mg but high in oxalic acid), bok choy has very low oxalate levels. This means a higher proportion of bok choy's calcium is available during digestion. Per calorie, bok choy provides 8.1mg calcium per kcal, compared to whole milk's 1.9mg calcium per kcal ^[1].

Cooking reduces bok choy's calcium to 93mg per 100g — a 11% loss, primarily from calcium leaching into cooking water. However, one cup of cooked bok choy (170g) still provides 158mg calcium, about 12% of the daily value.

For nutrition journaling, bok choy is particularly useful for tracking calcium intake from non-dairy sources. Its low oxalate content makes the logged calcium more representative of what's actually available — a tracking advantage over spinach and amaranth leaves, which have higher total calcium but more oxalate interference.

Baby bok choy (harvested early, ~75g per head) and mature bok choy (larger, ~200g per head) have the same per-100g nutritional profile. The USDA doesn't distinguish between them in nutrient data — both are classified as 'Cabbage, chinese (pak-choi)' ^[1].

The practical difference for food journaling is size: one head of baby bok choy (75g) provides about 10 kcal, 79mg calcium, and 34mg vitamin C. A mature head at 200g provides 26 kcal, 210mg calcium, and 90mg vitamin C. Log by actual weight rather than by 'number of heads' since sizes vary considerably.

The stem-to-leaf ratio differs: baby bok choy has proportionally more leaf and less thick white stem. Since the leaves contain more vitamin A and the stems contain more water, baby bok choy is slightly more nutrient-dense per gram in practice — though the USDA data treats them as one food.

One cup of raw shredded bok choy (70g) contains 9 kcal. Stir-frying it in 1 tablespoon of sesame oil adds 120 kcal, making the finished dish approximately 129 kcal — of which 93% comes from the oil. Adding soy sauce (9 kcal per tablespoon) and garlic (9 kcal for 2 cloves) brings the total to about 147 kcal ^[2].

Oil absorption in bok choy stir-fries varies by cooking duration and temperature. Quick high-heat stir-frying (2–3 minutes) results in less oil absorption than slower sautéing. For tracking, measure the oil before adding to the pan — any oil remaining in the pan after cooking represents calories not consumed.

For food journaling, bok choy stir-fries are straightforward to track: weigh the bok choy (13 kcal/100g raw), measure the oil by the teaspoon (40 kcal/tsp), and log the sauce separately. The vegetable component is so low in calories that even a 50% weighing error on bok choy changes the total by only 3–4 kcal.

Adding 100g of bok choy to a bowl of ramen or soup adds just 13 kcal to the broth while contributing 223mcg vitamin A (25% DV) and 45mg vitamin C (50% DV). The bok choy's 96% water content means it integrates into broth without significantly altering the liquid's calorie density ^[1].

Some nutrients (vitamin C, folate) leach into the broth during cooking, which means consuming the broth captures nutrients that would otherwise be lost with discarded cooking water. For soup-based preparations, the total nutrient intake is higher than for boiled-and-drained preparations.

For food journaling, log the bok choy separately from the broth. The broth's calorie contribution (from fat, protein, and seasonings) is typically 50–200 kcal per serving — far more significant than the bok choy. Track the bok choy by weight for vitamins and calcium, and the broth by recipe or brand for calories.